The field of the disclosure relates to commercial aircraft. More specifically, the disclosed embodiments relate to systems and methods for controlling the heating of a window in an aircraft.
At least some known commercial aircraft include a window heating system to provide heat to the windows, especially in the cockpit, to prevent the formation of ice on the window. Some such heating systems include two temperature sensors, a primary and a secondary, that measure the temperature as a change in resistance across the sensor. In at least some known window heating systems, when a user desires to switch temperature sensors because they suspect an error in the primary sensor, the user powers down the heating system and then powers it back up to switch between sensors. Such a system restart may be time consuming and cause ice to form on the window.
Additionally, in at least some known window heating systems, moisture may enter the window and cause a partial short circuit in one of the temperature sensors. A partial short circuit results in a reduced resistance across the sensor, which signals a false temperature reduction to the heating system and may cause at least some known heating systems to provide additional power to the heating element to increase the temperature of the window. However, in cases where the reduction in resistance is caused by a partial short circuit, and not a reduction in temperature, the additional heat provided by the heating element may result in a shortened service lifetime of the window.
Furthermore, in at least some known window heating systems, when a fault in one of the temperature sensors is detected, the heating system shuts down and terminates current flow to the heating element. Such a shut-down requires a manual interrogation of the heating system to determine the fault. The interrogation may result in a system restart to switch to another temperature sensor, or it may result in replacement of the window and window heating control system. Such manual interrogations are time consuming and may increase maintenance and labor costs associated with the aircraft.